640768230400 has 99 divisors (see below), whose sum is σ = 1588646819941. Its totient is φ = 256256061440.

The previous prime is 640768230373. The next prime is 640768230407. The reversal of 640768230400 is 4032867046.

It is a happy number.

The square root of 640768230400 is 800480.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 230676562944 + 410091667456 = 480288^2 + 640384^2 .

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (640768230407) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 128074299 + ... + 128079301.

Almost surely, 2^640768230400 is an apocalyptic number.

640768230400 is the 800480-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 640768230400

640768230400 is an abundant number, since it is smaller than the sum of its proper divisors (947878589541).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

640768230400 is an frugal number, since it uses more digits than its factorization.

640768230400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10036 (or 5010 counting only the distinct ones).

The product of its (nonzero) digits is 193536, while the sum is 40.

The spelling of 640768230400 in words is "six hundred forty billion, seven hundred sixty-eight million, two hundred thirty thousand, four hundred".